Lamp structure



Feb- 2, 1 B. LEVINSON ETAL LAMP STRUCTURE Filed Aug. 26, 1949 2 Sheets-Sheet 1 5m 5 N 2 W5 m N s 7 IL W M MM K e 5m V. .B A k Feb. 2, 1954 B. L; LEVINSON ET AL 2,668,228

LAMP STRUCTURE Filed Aug. 26, 1949 2 Sheets-Sheet 2 duce the 110 volts of the conventional external source to a 3 volt value suitable for the bulb. It has been found most convenient to utilize this step-down transformer as the means for separately connecting the bulb and the external power source, thus eliminating the necessity for awkward plugs and sockets. One portion of the step-down transformer is contained within the lamp base, this portion being hereafter termed the primary, and the other portion, hereafter termed the secondary, is a part of the lamp body, the primary and secondary being so arranged on the base and body, respectively, that when the body is secured to the basethe secondary is positioned adjacent to and in inductive relation to the primary. This mode of electrical interconnection, coupled with the spatial relationships between the primary and secondary and their positions on the base and body respectively, form an important part of the present invention independent of the provision of a second source of power. Even if a second source of power were not provided, this mode of connection permits the attainment, in a simple manner, of a desired low degree of illumination from a relatively high voltage source and in addition permits the replacement of a part of the lamp structure in a very simple manner. This replacement may be desired in order to provide a lamp of a different color scheme to go with a changed scheme of decoration or to substitute an undamaged for a damaged lamp body.

To the accomplishment of the foregoing objects and such other objects as may hereinafter appear, the present invention relates to a lamp structure as defined in the appended claims and as defined in this specification, taken together with the accompanying drawings, in which- Fig. 1 is a side elevational view of a lamp of the present invention showing the base secured to the body;

Fig. 2 is a side cross-sectional view taken along the line 2-2 of Fig. 1 showing the lamp body independently of the lamp base;

Fig. 3 is a side cross-sectional view similar to Fig. 2 but showing the lamp base independently of the lamp body;

Fig. 4 is a side cross-sectional view similar to Figs. 2 and 3 but showing the lower part of the lamp with the base secured to the body;

Fig. 5 is a schematic circuit diagram showing the basic electrical elements involved in the energization of the bulb from an external power source;

Fig. 6 is a schematic circuit diagram showing one mode of electrical circuit connections, corresponding to those shown in Fig. 2, when the lamp body contains a second power source;

Figs. 7 and 8 are schematic circuit diagrams showing alternative methods of electrical connection; and

Fig. 9 is a side elevational view showing the lamp of the present invention in use not as a table lamp but as a reading lamp adapted to be secured to a headboard or the like.

The details of construction of the lamp of the present invention, and the design thereof, may be varied within extremely wide limits in manners well known to those skilled in the art of lamp manufacture when compared to the speciflc disclosure. The present invention is independent of the construction either of the lamp body or the lamp base except as hereinafter more particularly pointed out in the claims.

The lamp of the present invention comprises a 4 base generally designated A and a lamp body generally designated B. This body is here disclosed in flashlight-like form because that form is considered to be extremely well adapted to the present invention but, as has already been pointed out, the precise form either of the base A or the body B lends itself to great variation.

The base A comprises a structural portion 2 shown in Figs. 1 through 4 as a type which is adapted to be placed upon a table top or the like. The upper part of this portion 2 is provided with a recess 4 and in that recess the first circuit portion 6 is secured, that portion acting as the transformer primary and, as here disclosed, taking the shape of a coil supported upon the bottom 8 of the recess 4 and preferably centrally disposed therein, a considerable space H) remaining in the recess 4 for a purpose hereinafter to be described. The base A is provided adjacent the recess 4 with a securing means, here shown as an externally threaded upstanding rim [2, adapted to cooperate with the lamp body B so as to detachably secure that body to the base A. The transformer primary or coil 6 is electrically connected to the wire [4 which extends out from the base A and which is adapted to be plugged into a suitable external power source in any conventional manner. A switch I6 is provided on the base A for connecting or disconnecting the transformer primary B to the external source of power and a pilot light l8 may be provided, if desired, to indicate when the transformer primary 6 is energized. Air passages 20 (see Fig. 3) may be provided in the bottom of the structural portion 2 of the base A in order to permit air circulation around the transformer primary 6, thus aiding in cooling the same. If desired, a bracket 22 may extend upwardly from the base A and may terminate in a dome-like reflector 24 to reflect and diffuse the light from the lamp.

The lamp body B comprises a casing 26 of any suitable material such as plastic, which casing is provided at its lower end with a securing means 23 in the form of an internally threaded depending flange cooperable with the externally threaded upstanding flange 12 of the base A in order to secure the body B to the base A. Depending from the body B and here disclosed as inside the depending flange 28 is a second circuit portion 30 which functions as a transformer secondary, this portion being here illustrated as a coil secured to and depending from an insulating plate 32 which is in turn secured to the body casing 26. This secondary coil 38 is so positiond on the body B that when the body B and base A are assembled, the secondary coil 33 will surround and be coaxial with the primary coil 6 and will be sufficiently close thereto so that it will be in inductive relation thereto, a transformer action thus taking place between the two coils 6 and 30.

Normal transformer construction calls for the placing of the primary and secondary as close to one another as is possible. In the lamp of the present invention, however, the necessity that the body B be readily removable from and replaceable on the base A requires that a considerable clearance be provided between the primary 6 and the secondary 3B. This clearance is also required by the manufacturing tolerances in constructing the coils 6 and 30 and securing them to the structural portion 2 of the base A and to the insulating plate 3-2 on the body B respectively, it being essential that the various bases and lamp bodies be used interchangeably. The clearanceis exengagement with the .tip -66 of the bulb 552'.

s-ea ingested iii the drawings for-purposesof clarity.

the primary 6 and the secondary 30,- a magnetizable core 34 of iron or the like issecured-to the bottom of the structural portion -2 of the base A inside, and preferably coaxial with, the primary coil 6. This core 3&- concentrates the flux generated by the alternating current passing through the primary coil 6 and thus causes effective induction of a corresponding current in the secondary coil 30.

One possible mechanical construction for-the lamp body B-is disclosed in Figs. 1 and 2. A substantially cylindrical casing 20 is provided, the casing being'apertured'at 36 so that switch button 38 may project therethrough. One or more batteries 40 may be received-within the casing 26, the batteries being here illustrated as of the-flashlight type. The top of the casing '26-may be externally threaded as at 42 and a conductiveplate 44 is adapted to be placed atop the casing 26, said plate 44 having a central aperture 45 through which the base 48 of a flashlight bulb 50 may be threaded so as to function as a socket for the bulb 50. The bulb base 48'acts as one terminal, the side terminal, for the bulb 50, the other bulb terminal being defined by its'tip 66, all in conventional manner. A'refiector 52 has a depending internally threaded flange 54 which cooperates with the externally threaded portion 42 of the casing 26, and-ribs or -ledges 56 on the interior of the reflector 52 act on the top surface of the plate 44 so as to retain that plate atop the casing 20.

The bottom of the casing 26 is defined by an open-ended housing 58 on the interior of which the plate 32 is secured and from which the securing means 28 depends. As here disclosed, the housing 58 is detachable from the casing 26 by means of the threaded engagement -60, but it could be made integral with the'casing 26 if that be desired.

Seouredto the plate 3'2 by means of rivet 62 is leaf spring 64 which tends to move upwardly and contact the underside-of the lowermost battery 48,- thus urging the battery 40 upwardly into A flexible lead '68 electrically connects the leaf spring 64 to acontact 10 positioned atop an upward protrusion 12 of the plate 232. A contact 14 is cooperable'with the contact :10, .the contact 74 being carried by arm I6 secured at one end to the plate 32 by means of rivet il8-andiurged downwardly toward the plate 32by1means of spring 853.

'Thesarm i is of.electricallyconductivematerial and has secured thereto a depending pin 82, pref- .erably of insulating material, which extends below the plate 32, projecting through the aperture 84 therein.

Various modes of electrical'connection may be provided. Fig. discloses in schematic form the basic electrical circuit, disregarding for the mo- ;ment the batteries 4i}. Two transformerecoupled circuits are provided, :one beingdefined by the wire I4 which is adapted tobe plugged into any available source of alternating current, the switch 7 IS, the pilot light I8 if desired,- and the primary coil 6 which surroundsthe magnetiza-ble core 34. The second circuit is defined by the transformer secondary 30 one end-of whichis connected to the side terminal as of the bulb .50 and the other end of which is connected to the tip terminal 66 current win-be indu edr n thesecq sl rrri whi h will in turn energize the bulb 50 ,and cause it-to illuminate. since, as has already been mentioned, the bulb 50 isof atypewhichis tobe energized'by flashlight batteries, it is incapableof withstandingthe full 110 volts of mean-ventional alternating current source. Accordingly, the transformer defined'by the primary (tend the secondary-30 m of the -stepdown type, the-ratio between the-turns being such that 110 volts supplied to the primary-coils will induce a voltage-of approximately 3 volts in-thesecondary coil 30 Figs. -6, 7 and '8 disclose" various modes of electrical connection in the lamp body 1B When a second electrical source, such as the batteries 40, is included therein. The-schematic diagram of Fig. 6- corresponds to the connections disclosed in Fig. 2. One end of the secondary coil 36 is connected by means of lead 86, which passes'through aperture 88 in the plate :32, to the side terminal 48 of the bulb '50, this-preferably being accomplishedmechanically by causing the end of the lead 86 -to-connect electrically with the conductive plate 44 into whichthe bulb 50 is screwed. The other end of the secondary coil 30 is connectedby means of lead- 90, which passes through aperture-92 in the plate 32-, to contact point 94. A separated contact point 96 is connected by means of'lead 98 to the tip terminal 68 of the bulb 50. Thus, whenever the contacts 94-and-96 are bridged-the bulb 50 will be electrically connected tothe-seoondary coil =30. The upper end of the battery 40-is electrically connected to the tip contact 66 of the bulb 350, this beingindicated in Fig.6 by the lead I00 but preferably being accomplished in the body *3 it self by directphysical contact as shownin "Fig. 2. The other end of the battery 40 is electrically connected to the leaf spring and from that spring, via the flexible lead 8,-to the contact point I0. The cooperating contact "I4 on the conductive arm I6 is electrically connected by means of lead I02 to contact point 104 -andseparated contact point I06 is electrically connected by lead I08 to the side terminal 48"of the bulb 50, which may be accomplished via conductive plate 44. Thus, whenever-the contacts I04 and I06 are bridged-the'bulb 50 will be electrically connected to and energized'by the battery'40. The switch button 38 is movable to at least'two positions, in one of which,;1llustrated=inBig. 6, the contacts I fi l-and I00-are "-bridged,;the contacts 94 and beingdisconnected, thus connecting the bulb 50 solely to the battery 40, and-in another of which the contacts-94 and 06 are bridged, thus connecting the bulb 5 0 -to-the secondary coil 30, thecontacts I 04 andI-OS being disconnected so as -to disconnect the bulb fromthe battery '40. If desired, an intermediateposition of the switch "button 38 maybe provided, in which neither of the contact pairst l, 9601 ?104,

I08 are bridged, the bulb '50 then being discon- .the spring ,8 0 wil1 pull the ,arm "16 downwardly,

as illustrated in Fig. 2, until the contacts I2 and I4 engage, thus closing the-circuit between them. When in this position placing the switch button 38 in the position illustrated in Fig. 6 will cause the bulb 50 to light, energized by the battery 40. When the contacts 12 and I4 are engaged, the plunger 82 will project downwardly an appreciable distance from the plate 32. When the body B is secured to the base A the depending tip of the plunger 82 will engage with a portion of the base A, here shown as the top of the magnetizable core 34, the plunger 82 thereby being raised so as to separate the contacts and H (see Fig. 4). As a result, it will be impossible to illuminate the bulb 50 from the battery 40 when the body B is secured to the base A.

This circuit arrangement has the disadvantage that, should the external power source fail, the lamp cannot be illuminated except by separating the body B from the base A. The circuit diagram of Fig. '7 is similar to that of Fig. 6 but eliminates the contacts 10, 14 and their associated mechanism so that the lamp 50 may be illuminated by the battery 40 if the external power source should fail.

Fig. 8 discloses an alternative switching arrangement somewhat more automatic in operation than that of Fig. 6. In this arrangement, the arm 16, the position of which is controlled by the plunger 82 and the spring 80, not only controls the position of the contacts Ill and H but also, via mechanical connection H0, controls therelative position of contacts H2 and H4. Contact H2 is connected via lead 99' to one end of the secondary coil 30, the other end of that coil being connected as before, by means of lead 85, to the side terminal 48 of the bulb 50. The contact I is connected by means of lead 98' to the tip contact 66 of the bulb 50. Whenever the body B is secured to the base A the plunger 82 will be moved upwardly, thus lifting the arm 16 and separating the contacts I0 and I4 so as to automatically disconnect the bulb 50 from the battery 40. At the same time, the mechanical connection H0 will cause the contacts H2 and H4 to engage, thus automatically electrically connecting the bulb 50 to the secondary coil 30. Hence, whenever the body B is secured to the base A and the switch 16 in the base A is closed,-the bulb 50 will be energized and illuminated by the external power source. As soon as the body B is separated from the base A, the spring 80 will move the arm 16 downwardly, thus separating the contacts I I2 and H4 and disconnecting the bulb 50 from the secondary coil 30. At the same time the contacts ID and M will engage, thus automatically connecting the bulb 50 to the battery 40 and causing automatic energization and illumination of the bulb 50 by the battery 40. If desired, a make and break switch of conventional type may be employed corresponding to the contacts 104 and 106 so that, even when the body B is removed from the base A, the bulb 50 can be illuminated or not at will.

In Fig. 2 the electrical connections are illustrated more or less schematically and may take the form of wires, flexible metallic strips, or the like, all as well known in the art.

'Fig. 9 illustrates another embodiment of the f present invention in which the lamp base A is not of the table-supported type but is instead mounted on a ball and socket joint H6 which is carried by a clamp H8 adapted to be secured, .by means of screw I20, to a bed headboard I22 or the like. in this embodiment the lamp is adapted .light type illuminator and yet retains all of the advantages heretofore set forth. This is but exemplary of the many uses to which the lamp may be put and is indicative of the many shapes and designs which it may assume.

The lamp of the present invention has the basic advantage that it permits the use of low voltage bulbs with relatively high voltage alternating current sources by means of a step-down transformer circuit arrangement, that arrangement facilitating removal and replacement of the lamp body or the lamp base. The lamp of the present invention has the further important advantage, when the lamp body is of the type which carries within itself a second source of electric current such as the batteries Ml, that it may be used in fixed position so as to be energized by the external power source but can be moved about, at which time it will be energized by the second power source carried within the lamp body B, the body B being removable from the base A for that purpose. The lamp is also rendered substantially independent of failure of the external power source, since the batteries 48 may be utilized for illumination whenever that event occurs. In addition, the lamp body B may be separated from the base A and used as a conventional flashlight or the like, thus providing in a single structure a stationary lamp having a unitary appearance and a portable flashlight. Thus, it will no longer be necessary for an individual to purchase both a stationary night light and a flashlight.

The present invention has been here disclosed structurally in but two forms, and a few exemplary circuit arrangements have been shown each having advantages and disadvantages when compared to the other. It will be apparent that the specific disclosure may be varied in many respects without departing from the spirit of the invention as defined in the following claims.

We claim:

1. A lamp comprising a base having a recess therein, an annular transformer primary coil in said recess but only partially filling the same, a body including a bulb, means for separably securing said body to said base, an annular transformer secondary coil depending from said body and positionable in said recess, the internal diameter of one of said coils being greater than the external diameter of the other of said coils and said coils being positioned substantially concentrically in inductive relation when said body is secured to said base, and an electrical connection in said body between said secondary coil and said bulb.

2. The lamp of claim 1, in which the voltage relationship between primary and secondary coils is of a step-down nature and on the order of magnitude of to 3.

3. In the lamp of claim 1, a second source of electric power in said body having a voltage comparable to the voltage rating of said bulb, an electric circuit between said second source and said bulb, and a switch connected in said circuit and in the electrical connections between said secondary and said bulb effective to connect said bulb either to said second source or to said secondary.

4. In the lamp of claim 2, a second source of electrical power in said body having a voltage comparable to the voltage rating of said bulb, an electrical circuit between said second source and said bulb, and a switch connected in said circuit and in the electrical connections between 1 Number Name Date said secondary coil and said bulb efiective to con- 728,789 Wellman May 19, 1903 nect said bulb either to said second source or to 1,755,385 Beidler Apr. 22, 1930 said secondary coil, said switch having a portion 1,922,079 Dixon Aug. 15, 1933 cooperable with said base when said body is 5 2,133,494 Waters Oct. 18, 1938 secured thereto and efiective to move said switch 2,389,762 Burke Nov. 27, 1945 to a position in which said bulb is connected to said second source. FOREIGN PATENTS BENJAMIN L. LEVINSON. Number o y Da e JACK KORSHIN m 462,458 .France Jan. 28, 1914 References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 723,836 Cowing Mar. 31, 1903 15 

